#include<stdio.h>
#include<assert.h>
char* my_strcat(char* dest,const char* src)
{
	assert(dest && src);
	char* ret = dest;
	while (*dest != '\0')
	{
		dest++;
	}

	while (*src != '\0')
	{
		*dest++ = *src++;
	}
	*dest = *src;
	return ret;
}
int main()
{
	char s1[20] = "Hello";
	char* s2 = "World";
	printf("%s", my_strcat(s1, s2));
	return 0;
}